Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, power conversion and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various layers using lithography to form circuit components and elements thereon.
A transistor is an element that is used frequently in semiconductor devices. There may be millions of transistors on a single integrated circuit (IC), or only a single transistor with a large gate periphery to conduct large currents, for example. A common type of transistor used in semiconductor device fabrication is a metal oxide semiconductor field effect transistor (MOSFET), as an example. A transistor typically includes a gate dielectric disposed over a channel region in a substrate, and a gate electrode formed over the gate dielectric. A source region and a drain region are formed on either side of the channel region within the substrate.
Metallization layers are formed over the transistors. The metallization layers include interconnects for interconnecting the transistors and also to contact pads for contacting the transistors with external circuitry. The circuitry used to contact the transistors can introduce significant parasitic effects, which can degrade the performance of the transistors.